Dynamo-electric machine.



M. E. THOMPSON.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED JUNE 23. 1910.

1,048,006. I 'Patented D eb.24,1912.

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DYNAMO ELECTRIC MACHINE.

APPLICATION FILED JUNE 23. m0.

Patented Dec. 24, 1912.

4 SHEETfi-SHEET 2 M. B. THOMPSON. DYNAMO BLEOTRIG MACHINE.

APPLICATION FILED JUNE 23. 1910.

Patented Dec;24,1912

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M. E. THOMPSON.

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UNITED STAT'lllte MILTON THOMPSDN, 01 l. IDGWAY, l iillill lfilftlft 'filillg.

Application filed Ilene 23, 1910.

To all whom it may concern:

Be it known that I, MILTON E; Tnoizrson, a. citizen of the United States, and a resident or" Ridgway, Elk county, State of Pennsyl- Vania, have invented certain new and useful improvements in Dynamo Electric Machines, of which the following is a specification.

My invention relates to improvements in dynamo-electric machines or electric generators and motors and is more especially directed to improvements 'in that type of machine shown and described in Letters Patent No. 591,024, granted to me October 5th,1897.

The dynamo of that patent is provided with a cast iron ring interposed between the main field cores and armature. This forms an especially eflicient and simple means upon which balancing coils may be located and at the same time provides suitable interpoles' and commutation lugs with a minimum amount of windings and expenditure of ener y. I have found, however, that in the construction of the machine as set forth in said Letters Patent that there is a certain leakage flux between the main poles of the machine through the outside part or" the cast iron ring. This leakage flux could not be utilized in any way and made the machine less eflicient than it otherwise would he and necessitated amore liberal amount of material in all parts of the field structure therefore making the machine heavier, more ex pensive and less etlicient than it would otherwise be.

It is the principal object ofmy present invention to obtain all the advantages of my said former machine while avoiding this leakage flux and the resultant harm therefrom. To this end in my improved dynamo I have constructed the main pole pieces and interpoles as independent members securing them together alternately in such a way that when assembled they constitute in substance the ring of my former patent but with the interpolcs separated from the main pole pieces by a, sufficient magnetic gap at all points to enable the desirable results obtained from my'former structure to be obtained while preventing the leakage that ere isted in that former structure. The interpoles are supported from the main pole specification oi Letters latent.

Patented Bree. 1912.

Serial l lo. 559,454.

pieces by brass keys while the main pole pieces are supported in place by being separately bolted to the main frame and the cores projecting therefrom. The interpoles are thus although magnetically separated by small gaps from the pole pieces and from the armature, yet so much more magnetically separated from the main frame that the flux flowing through the interpole is derived from the main pole pieces without interfering or substantially affecting the flux in the frame itself.

While I prefer the precise construction I have briefly described and which I will describe more at length hereinafter with reference to the drawings, yet my invention in its broader phase is not limited to all the precise features which I have thus far mentioned.

Further objects, features and advantages will more clearly appear from the detailed description given below taken in connection with the accompanying drawings which form a. part of this'specification.

lln the drawings, Figure l is a side view of a dynamo-electric machine embodying one form of my improvements, certain parts being omitted. in order to more clearly show the structure thereof. 2 is transverse section oi the machine taken on the line ill-H of Fig. 1, Fig. 3 is a transverse section of the machine taken on the line liI'-IHI of Fig. 1. Fig. 4 is a side view showing the shape and arrangement of the laminations forming the auxiliary cores or magnetic structures. Fig. 5 is a. detailed top plan View of laminations forming the aux iliary cores or magnetic structures and showing the arrangement or" the same. Fig. 6 is a transverse section taken on the line Vi i l of Fig. 7 is a bottom plan view of the laminations of Fig. i showing in detail. their arrangement and. also diagrammah ically' showing the method of winding the Same.

Rel-owing to the drawings, 1 represents a main frame composed of circular ribs 2 and circularly arranged laminations 3. As

shown there are three of the ribs 2 and .turcs s be clearly that the same air spaces in the sea may be ccoied. ing blocks, ieiiiiiieticns ii ribs 2 we securely bound together by means of bolts 5 forming a rigid circular field "came structure. Allfillgd wiihiii iihis sirucwzeemi adjacent thereto are suitebiy space/(i iiclcl cores 6 for (nu-lying the main fieid windings T. These main. field cores are also formed of lsminetiens have certain of the hunt nations omitiefi and spacing blocks 8 interposcci, as already described with respect to the himiiiations The iemineiions forming the main field. cores (3 are rigidly beuncl together by means of bolts 9 Vfitiiin the circular structure formed. by the field frame anci the ieiri cores 6 is the armature 10 which may he of any Well known form and construction. fihe urine,- ture 1.0 has a diameter considerably less than that of the bore of the series of field cores. interposed between eecn icl core 6 marl the mince 10 is an auxiiisry magiieiic sizi'uclim'e pi'eferel'ily formed cf lamina; ticns 11 an. pi'o'vi ied with cast iron plates 12 forming the end. pieces of these structures. in l 'ifihe windings have been removed from part of these auxiliary strucshoW the shape of the cast iron pistes l2 and on a portion of that figure the cast. iron pistes have been reznovei in order to clearly show the shape of the laminei-ioiis 11. The shape of the laminzitions 11 is also clearly shown in detail in 4. These auxiliary field. structures are built so of these im'ninetions as clearly shown in Figs i 5 and and siiitiibie air spaces 13 {we provided therein. by the omission cf certain 01? the iamiiiations and (he inclusion cf spacing hiccizs 142 {see Figs. 2, 4i and 5). The hmiinetions 11 and hicchs 1 are rigidly secured together to form a vfirm 15 ma l cic structure by means of boii's ans 1G. The holis- 15 end 16 and the s 121cing (flecks are on'iihte from Fig. '6' for she keof? deafness The various magnetic structures formed. 0 the leminetioi s .l zuni 021st 12 secured 5o i'he Hi .1 cores 6 and fieicl 3, by means cf bolts 17 which 1 mm the outsicie of theTield frame down. through the cores 6 and iniie threaded openings 18v within {he laminations 11', (see l, 2-, 3 211515). It wi l thei'efoi'e, he seen that the magnetic si-iuctilics 01 mm cf the ieminetions 11 intei'pos n between the main fieid cores 6 and "the sui'zeiure 10 and are miviclua-iiy was se'eeireteiy secured er fastened to said co; s

mid 'ehecehy he the field frame and lie in places molleiiy' the same that or? held cores intei'posed between the field 6 and she ermat' ie i0 and lynig he 1 y nmgnci-lc strucof lsniinseioiis ii,

The vsri 011s spactures forme 0i leminzitions 19. These m21g2- netic structures zirmnge to fiorm intec poles or coniniutsiion lugs and on each end thereof are provided cast iron plates :20.

The shape of these plaies is clcarzy shown in Flg. l and the shape of the lammsiiions is cleari Y shcwn in Fi t 1 and 4:. The struc- 93 tux-e formed of these leminations 19 and S20 is mecie rigid by means bolts 21 ancliZtZ passing the1ethrough. These auxiliary magneeic structures formed of laminations 19, etc, are magnetically separated from the structures formed of the laminatiens 11 by shori spaces 22 but are secured to the structures formed cf the laminetions ll, eic., by means of brass keys :23, inserted in slots in the various lill'lliilZLlZiOIlS. By the farm spaced. magnetically or "magnetically separated 1 mean. that the gaps between the magnetic structures 11 and 27 are not substantially bridged by any material having any considerable magneiic COHCiUCtiVilL-y but I do not mean shat flux crossing such gap is not intended to be utilized in the opera den of the machine for as I will" show i make use of this flux for the commutation.

i The parts so far described are assen'ibleci by first forming the pole cores 6 and she auxiliary sii'uctuires 11 and making them rigid structures by means of the bolts already described. structures are then rigidly secured to the field frame of the machine by means of the bolts 17. The interpo-le structures formed of leminations 19 are then, assembled and made rigid by means of bolts 21 and 22 and these are slipped in between the structures formed. of laminations i2 and properly secured thereto and to the frame of the ma chine xiii-mm; of the brass keys Q3. The venous auxiliary magnetic structures formed of lzmiinetions 11 and 19, etc, are

thus arranged in the form of a. ring incerposed between the main field cores and the armature 10. Each incerpole strucb'ure formed of iamineiions 19 is provided with suitable air spaces therein by the omission. of certain of the leminat-ions and the inclusion of suitable spacing members 2% see After ussembiing the part-s as time dethe various magnetic structures:

formed 01 lamination I in. piece as'riescribeii and the main field coils 7 slipped on the field cores 6 the'balancing windings 28 are put in place. The method of winding these is well known but will be clearly an erstood from a consideration of Fig. 7. The wire 28 indicated on that figure shows the direction in which the windings go. Starting at 'the arrow 29 the windings pass in about the laminations 19 of the interpole structure through the space 22, then back through the space 22 on the opposite side of. said structures, then the windings pass through the slot 26 of one of the structures formed of laminations 11 and back through the slot 26 of the adjacent structure formed of laminations 11. Thence the winding passes through the slot 25 of the first mentioned structure formed of laminations 11 and then back through the slot 25 of the second mentioned structure formed of laminations 11. Then'the winding passes to the next series of auxiliary structures and is wound thereupon in a similar manner but in the opposite direction. This winding is connected to be responsive to the armature current in the well known manner and is clearly described in my prior patent above mentioned, so that the windings will act to provide a proper interpole flux through the auxiliary structures formed of laminations l9 and will also provide a proper balancing magnetomotive force in the various auxiliary magnetic structures, the axis of which will lie in a radial plane between the axes of the main field cores.

Some of the laminations 19 are made wider than others'at the top portion thereof, as shown at 31, in order to properly reduce the air gap between these laminations and the adjacent laminations 11. By varying the number of laminal ions 19, which are provided with the extensions 31, the reluctance of the magnetic path from the inter-pole to the adjacent auxiliary magnetic structuremay be-varied as desired.

In operation the windings 28 act as balancing coils or compensating windings to properly compensate for the armature re- At the provide the proper interpole flux for the commutation lugs formed of laminations 19.

After the parts are assembled the shortest distance between the interpole and the frame is much greater than the gap between the interpole and adjacent pole piece so that substantially none of the flux utilized in the interpo-le passes through the gap between the interpole and the frame. As a result-the flux utilized in the interpole does not interfere with or substantially vary the flux in the main frame passing from one main core to the next: Previous to this invention those who had endeavored to provide interpoles separated from the main pole pieces in any from one another, and

practicable machine so constructed the field structure that the interpole flux passed through the frame of the machine causing in the first place a constant leakage flux from each main pole through the interpole and in the second place causing such an inequality in the flux at different parts of the frame as to seriously interfere with the proper compounding of the machine. I have at the same time utilizedthe main field frame and pole pieces to carry the flux utilized in the interpole and avolded the passing of the flux directly fromthe inter-pole to the frame with the disadvantages I have indicated. W'hile obtaining these results I have avoided anysubstantial leakage of the main flux.

My present invention also enables a certain compounding of the machine by the eccentricplacing of the compensating windings which could not be practically done heretofore except with the machine of my former patent.

In referring to the relatively short gap between each interpoleand its adjacent pole piece I do not, of course, refer to the distance between the pole tips of interpole and main pole as that does not form any part of the magnetic circuit of the interpole. Such flux as might pass between the tips of these portions of the magnetic circuit would be harmful because opposing the eiiective flux and there is no functional relation between thisgap and the gap between the int'erpole and the main frame. The relatively short gap between interpole and main pole that is important is that which exists between the back of the interpole and the back of the main pole piece, this being at a point between the compensating winding and the main field winding, and enabling the interpole, although separated by a gap from the main pole, to nevertheless derive its fi'ective flux therefrom.

Aside from the above advantages the arrangement is especially advantageous for its accessibility and easy removal of parts. If

it is desired to remove any one of the main field poles 6 with its windings 7 the same may be done without removing substantially any of the other parts of the machine. It is only necessary to remove the bolts 17 corresponding to that field pole when the field pole structure may be readily slipped outward laterally. -In a similar manner the various auxiliary magnetic structures may be removedlaterally by simply removing the windings therefrom and then removing the adj acent' brass keys 23 and bolts 17 when they may he slipped out laterally without;

Thea:

removing any remaining structure; great advantage of thus having the various auxiliary magnetic structures in the form of a ring, the parts of which are separable independently semagnetic member; supporting each interpole, land compensating windings carried by said pole pieces and interpoles.

j In a dynamo, a field frame with pole -cores and windings thereon, separate pole pieces fastened to said pole cores, interpoles e. placed between said pole pieces, theouter ends of the said interpoles being separated from said pole pieces by a short gapiand from the frame y along gap, the relative gaps being such as to permit the effective flux for the interpoles to be received from.

gether with magnetic gaps between them, i

and a field frame magnetically connecting the main pole pieces,'the interpoles being spaced with reference to the main pole pieces and frame to permit their efi'ective flux to be received from the main poles.

12. In a dynamo, a field structure having cores and pole pieces separably secured thereto, windings on said cores, interpoles magnetically separated but mechanically supported from the polcpieces,the outer ends of the interpoles not extending substantially beyond the inner ends. of said windings, and auxiliary windings surround ing said .interpoles said interp'oles receiving their flux from the main pole pieces at points between said two sets of windings.

- In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

' MILTON E. THOMPSON.

Witnesses:

A. R. MEEK, J. M. SCHRAM. 

